Vehicle lifts fitted to vehicles have long been known. They serve to convey articles or people from the interior of the vehicle to the exterior and back again if there is a difference in level between the level of the interior of the vehicle and the location at which the articles or people are to be placed, or if there is a gap which has to be bridged over. An important application for such vehicle lifts is in vehicles in which wheelchair users are transported. Such a vehicle lift of the general kind set forth, to the present applicant, is disclosed for example in DE 203 09 868 U1.
Known vehicle lifts have a platform which is pivoted movably to at least one support pillar and is moved by means of a lifting device. In general a distinction can be drawn between at least two main positions. The first retracted position is the retracted position, during which the vehicle lift is not used. The platform is then generally in a vertical position so that the entire vehicle lift takes up as little room and space as possible and does not interfere while travelling with the vehicle.
In the second extended position, the vehicle lift is extended and the platform is disposed substantially horizontally near the ground so that, for example, a wheelchair user can easily go from the ground on to the platform. In most cases, there is also an intermediate position in which the platform is approximately at the level of a vehicle interior so that, for example, a wheelchair user can travel from the platform into the vehicle interior. Between the intermediate position and the second extended position the platform is lowered substantially parallel to itself by means of the lifting device.
Particular significance is attributed to the support pillar of such a vehicle lift. First, it is connected on the one hand to the lifting device which causes the movement of the platform and, on the other hand, the platform is pivotably mounted to the support pillar. Consequently, all forces and moments from the platform are transmitted to the vehicle by way of the support pillar. Therefore, such a support pillar on the one hand must bear and withstand such forces while on the other hand the support pillar must be so designed that the vehicle lift can be arranged in the vehicle in a condition of occupying as little space as possible, in the first retracted position. In addition, the support pillar should be light to avoid unnecessary additional weight due to the vehicle lift. Previous support pillars for that purpose generally comprise a steel carrier having a multiplicity of weld seams so that it is put into the shape of the support pillar. Weld seams have a number of disadvantages. On the one hand, a welded seam always signifies one or more additional working steps such as cutting, preparation, welding, cleaning and so forth. On the other hand, weld seams in dynamically and alternatingly loaded components generally represent particular weak points.
Therefore the object of the present invention is to provide a vehicle lift, a support pillar and a production process which are at least partially improved in respect of the above-mentioned problems.